Heretofore, a ligation treating apparatus as shown in FIG. 4 is known. This ligation treating apparatus is provided to the tip of an endoscope A and used when ligation of varicose vein in the esophagus or other organs is performed. In a case where multiple varicose veins exist, this ligation treating apparatus is capable of conducting ligation of the multiple varicose veins without the need to take the endoscope in and out of the body cavity of patient.
Hereinafter, the conventional ligation treating apparatus will be described more specifically. This ligation treating apparatus, as shown in FIG. 4, has a plurality of elastically diameter-expanded ligation rings B on an inner cylindrical portion 30 which is connected to the endoscope A. An outer cylindrical portion 31 is provided to the outer side of the inner cylindrical portion 30, and a cylinder portion 32 is formed in space between the inner cylindrical portion 30 and the outer cylindrical portion 31. In the cylinder portion 32, an annular piston member 33 which can move back and forth freely along the external wall of the inner cylindrical portion 30 is provided. Further, a tube 34 is connected to the cylinder portion 32, and fluid is introduced into the cylinder portion 33 via the tube 34. At the base end of the tube 34, a syringe is connected as means for sending fluid forcibly, for example. The tip of the piston member 33 is in direct contact with the rearmost ligation ring B.
To perform ligation, firstly, a varicose vein is sucked into the inner cylindrical portion 30. Then, fluid is introduced into the cylinder portion 32 so as to move the piston member 33 forward. This action causes the piston member 33 to push the ligation rings B forward, and the foremost ligation ring B is released from the front end of the inner cylindrical portion 30 so as to ligate the varicose vein. When other varicose veins are to be ligated without taking the endoscope A out of the body cavity of patient, each of the varicose veins is sucked into the inner cylindrical portion 30 and the above procedure is repeated.
Thereby, a plurality of varicose veins can be ligated in a short time without the need to take the endoscope A in and out of the body cavity of patient. As a result, the pain of the patient can be alleviated.
However, according to the above conventional ligation treating apparatus, there is a possibility that a plurality of ligation rings B may be released from the front end of the inner cylindrical portion 30 simultaneously for a single varicose vein if fluid is introduced abruptly upon operation of the syringe. Accordingly, the syringe must be operated carefully so as to release the ligation rings B from the front end of the inner cylindrical portion 30 one at a time, and such a careful operation of the syringe requires a skilled operator. This is a disadvantage of the conventional ligation treating apparatus.
Thus, an object of the present invention is to eliminate the disadvantage and provide a ligation treating apparatus which has a plurality of ligation rings and is capable of performing ligation on varicose veins on multiple sites quickly and releasing the ligation rings from the front end of an inner cylindrical portion one at a time with certainty.